Gaseous electric discharge device



June 7, 1932. H. KRESSIN 1,861,633

GASEOUS ELECTRIC DISCHATQGE DEVICE Filed July 21, 1931 INVENTOR BY 95m, mm

WkZZa-v ATTORNEY l atented June 7, 1932 unrran s r rss PATENT orrc "RI EARS KBESSIN, F IBERLIN-BRI'IZ, GERMANY, ASSIG-NOR T0 GENERAL ELECTRIC COMPANY, A. CORPORATION OF NEW YORK Gaseous nnncrarc, nrsonanen nnvrch Application filed July 21, 1931, Serial No. 552,260, and in Germany August 15, 193e,

The present invention relates to gaseous electric discharge devices generally and more particularly the invention relates to a means for feeding gas replenishments to the gaseous 6 atmosphere of said device.

It is well known in the art that common gas, such as carbon dioxide and nitrogen, cleans up when used in the gaseous atmosphere of an electric discharge device with disastrous effects to the operating characteristics of the device. Many means have been proposed to feed gas replenishments to the device, such as the well known Moore valve, but such devices have not proven of great practical value due to the I inaccuracy in amount of the gas replenishments they sup plied to the device, The object of the present invention is to provide means for the accurate feeding of common gas replenishments 2 to the gaseous atmosphere of a gaseous electric discharge device. A further object of the invention is to provide such means having no moving parts Still further objects and advantages attachiug to the device and to its use and operation will be apparent to those skilled in the art from the following particular description and from the appended claims,

In accordance with these objects the in- 39 vention comprises a heating filament for a common gas evolving material in the container of the device, said heating filament is connected to the secondary coil of a stepdown transformer, the primary'coil of said as transformer is connected to the low voltage part, near the zero point, of the secondary coil of a leaky, or high reactance transformer, the primary coil of said leaky transformer is connected to the terminals of a current source of commercial voltage. Due to the high inductive otential drop of the leaky transformer an the smoothing effect of the step-down transformer this circuit arrangement prevents fluctuations in the potential of a; the supply circuit of the discharge device from affecting the heater filament so that said filament is maintained at a constant temperature to cause a steady heating of the common gas evolving material which feeds common gas replenishments to the device at a steady rate. If the gas pressure in the container of the device drops the potential of the transformer circuit decreases and the current increases so that the heating filament is brought to a higher temperature "to increase the rate of feeding gas replenishments to the device. Thus the feeding of gas replenishments to the device is controlled solely by the conditions of the gas pressure therein, the effect of fluctuations of potential in the current supply circuit on the heater of the gas evolving material being practically nil,

In the drawing accompanying and forming part of this specification an embodiment of the invention is shown in side elevation the circuit being shown schematically for purposes of disclosure.

Referring to the drawing the gaseous electric discharge device comprises a container 1 having a filling of gas therein consisting m wholly of a common gas, such as nitrogen or carbon dioxide, or a mixture of such gases with a rare gas or a metal vapor. Electrodes 2 and 3 are sealed in said container 1, said electrodes are of the type which glow and emit electrons during the operation of the device though any other suitable ty e of electrode may be used if desired; aid electrodes 2 and 3 are connected to the splitcoil secondary 6 of a high reactance, or leaky transformer 6-7 by leads 4; and 5 respectively. The primary 7 of said leaky transformer 67 is connected to the terminals of a current source of common commercial voltage by leads 8 and 9. A rod 11 consisting of 5 a material. such as magnesium carbonate or sodium azide, which evolves gas when heated, is supported in ofi-set chamber 10 by metal rod 12 sealed into the stem of said chamber 10. Said rod 11 is surrounded by a heater filano ment 13, said filament 13 is connected to the secondary 16 of a small step-down transformer 16-17. The primary 17 of the latter is connected to the low voltage part of the twocoil secondary 6 of a leaky transformer 67 at ap roximately the zero point 18 thereof in sudh manner that the primary 17 of the step-down transformer 1617 bridges over the two coils of the secondary 6 of the leaky transformer 67.

During the normal operation of the gaseous electric discharge device the filament 13 is maintained at such temperature that the common gas replenishments evolved by the common gas evolving material 13 is slightly less than needed to maintain normal condi tions of gas pressure in the container 1. A slight drop in gas pressure causes a corresponding rise in the current across the gaseous electric discharge device so thatthe'filament 13 is brought to a higher temperature to cause a greater evolution ofga's. As soon as the gas pressure is restored to normal the current on the device drops and thelieating filament is less strongly heated so'fthat the gas evolving material again evolves slightly less gas than needed. Fluctuations in potential 1n the current supply circuit have little or no effect on the temperature of filament 13 due to the high inductive potential drop of the leaky transformer 67and the smoothing effect of the step-down transformer 1617 as explained heretofore.

'What I claim as new and desire to secure by Letters Patent inthe United States, is:

1. In an electric discharge device, a filling of gas supporting an electric discharge, a material for supplying the desired gas to the discharge device and a heating means for causing liberation of gas from said material to replenish the gas filling of said discharge device, said heating means being connected to the low voltage part of the high voltage side of a high reactance transformer for the discharge device, to diminish the efiect on the heating means of potential changes in the supply circuit of said discharge device.

2. In an electric discharge device, a filling of gas supporting an electric discharge, a material for supplying the desired gas to the discharge device and a heating means surrounding said material for causing liberation of gas from said material to replenish the gas filling of said discharge device, said heating means being connected to the low voltage part of the high voltage side of a high reactance transformer for the discharge device through a step-down transformer to diminish the effect on the heating means of potential changes in the supply circuit of said discharge device.

3. In an electric discharge device, a filling of gas supporting an electric discharge, a material for supplying the desired gas to the discharge device and a heating means for causing liberation of gas from said material to replenish the gas filling of said discharge device, said heating means being a coiled wire surrounding said material and being connected to the low voltage part of the 

